(a) Field of the Invention
This invention generally relates to a pushbutton lock that includes a shield or anti-theft feature about the pushbutton. More particularly, but not by way of limitation, to a pushbutton lock with a freely rotating collar around the pushbutton of the lock.
(b) Discussion of Known Art
Pushbutton locks, or the use of lock mechanisms that are opened or activated by way of a pushbutton are widely used. An important advantage to the use of these locks is that they can be easily installed in devices that are made from sheet metal or plastics. For example, the use of a pushbutton lock in storage boxes or lockers, such as the tool boxes or lockers used with pickup trucks or service trucks has nearly become an industry standard. Unfortunately, however, the pushbutton lock suffers from a serious security weakness in that many of these installations can be easily overcome with the use of a pair of pliers or a pipe wrench. To defeat the lock mechanism, the thief simple grips the protruding pushbutton with a pair of pliers or a wrench, and turns the pushbutton. The pushbutton is linked to a cam that contacts a latch actuator when the pushbutton lock is in an unlocked position. The contact of the cam with the latch actuator allows the lock mechanism to open by pressing the pushbutton. Pressing of the pushbutton causes the cam to move against the latch actuator, which in turn releases the lock mechanism, causing the lock mechanism to open. Thus, the cam is turned away from the latch actuator when the pushbutton lock is in the locked position, preventing contact of the cam with the latch actuator. Thus, a thief can defeat a pushbutton lock mechanism by simply turning the pushbutton to a position where the cam contacts the latch actuator mechanism. The pushbutton is easily turned with the aid of a pair of pliers, a pipe wrench, or the like.
Many artisans have approached the problem of tampering with locks by providing a shield or guard mechanism. However, pushbutton locks have remained vulnerable to thieves. Therefore, a review of known devices reveals that there remains a need for a system for preventing thieves from turning the pushbutton of a pushbutton lock. This protective mechanism should be simple, so that the mechanism does not complicate the simple installation process that is germane to the pushbutton lock mechanism. In other words, there remains a need for a system that protects pushbutton locks, and which does not involve creating a separate protective that is mounted on the lockbox or container that relies on the pushbutton lock.
Still further, there remains a need for a theft or tamper resistant pushbutton lock that can be installed using the same preparation and installation procedures as known pushbutton locks.
There remains a need for a pushbutton lock that prevents the turning of the pushbutton to prevent unauthorized access through the pushbutton lock.
It has been discovered that the problems left unanswered by known art can be solved by providing a pushbutton lock that includes a rotatable shield around the pushbutton. Briefly stated, the invention includes a pushbutton that releases the latch mechanism, and a shield that is rotatably mounted around the pushbutton, so that the shield does not prevent the user from activating the pushbutton, but prevents the gripping of the sides of the pushbutton with a pair of pliers, wrench or similar tool.
According to one example of the invention the pushbutton lock includes a housing that is adapted for extending through a support panel, such as the lid of a box that is to be locked with the use of the pushbutton lock. The housing includes sides and a bottom. The bottom of the housing includes an aperture that allows the extension of a shaft that supports the cam that activates the latch mechanism of the lock. The shaft is connected to a cylinder that holds the lock""s tumbler or key mechanism. The pushbutton is mounted against the cylinder, and is allowed to extend from the housing by way of a pushbutton opening in the housing, at a location opposite to the bottom of the housing.
In known pushbutton locks a spring is held within the housing, positioned between the bottom of the housing and the pushbutton. This spring urges the pushbutton outwardly from the housing. In one example of the disclosed invention, a collar is positioned around the pushbutton. In this example the collar includes sides and a bottom. The bottom of the collar includes an aperture that allows the cylinder mechanism or shaft to extend though the bottom. Thus, the spring will be positioned in the housing between the bottom of the housing and the collar. The pushbutton will be positioned within the collar.
Of course, it is contemplated that the collar may be simply cylindrical with an aperture of a generally constant size extending through the cylinder. With this configuration a retainer, such as a circular spring that nests in mating grooves in the pushbutton and the collar or a protruding element that extends from the pushbutton or the collar and into a grove in the mating part. Additionally, it is contemplated that other mechanisms, such as a bearing or other rigid component that resides in a common groove or similar engagement mechanism.
Thus, the collar will extend over the pushbutton, and prevent direct contact with the sides of the pushbutton. This will prevent thieves, or others trying to defeat the lock, from engaging and rotating the pushbutton to turn the shaft and accompanying cam in order to activate the latch mechanism and open the lock.
It should also be understood that while the above and other advantages and results of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combinations and elements as herein described, and more particularly defined by the appended claims, it should be clearly understood that changes in the precise embodiments of the herein disclosed invention are meant to be included within the scope of the claims, except insofar as they may be precluded by the prior art.